Bump Security String to 2020-08-05

Implemented:
============
CVE:            References:     Type:   Severity:       Updated AOSP versions:
CVE-2020-0108   A-140108616     EoP     High            8.1, 9, 10
CVE-2020-0238   A-150946634     EoP     High            8.0, 8.1, 9, 10
CVE-2020-0241   A-151456667     EoP     High            8.0, 8.1, 9, 10
CVE-2020-0247   A-156087409     DoS     High            8.0, 8.1, 10
CVE-2020-0256   A-152874864     EoP     High            8.0, 8.1, 9, 10

Previously Implemented:
============
CVE:            References:     Type:   Severity:       Updated AOSP versions:
None

Not Implemented:
================
CVE:            References:     Type:   Severity:       Updated AOSP versions:
None

Not Applicable (platform source):
=================================
CVE:            References:     Type:   Severity:       Updated AOSP versions:
CVE-2020-0239   A-151095863     ID      High            9, 10
CVE-2020-0240   A-150706594     RCE     High            10
CVE-2020-0242   A-151643722     EoP     High            8.0, 8.1, 9, 10
CVE-2020-0243   A-151644303     EoP     High            8.0, 8.1, 9, 10
CVE-2020-0248   A-154627439     ID      High            10
CVE-2020-0249   A-154719656     ID      High            8.0, 8.1, 9, 10
CVE-2020-0250   A-154934934     ID      High            10
CVE-2020-0257   A-156741968     EoP     High            10
CVE-2020-0258   A-157598956     ID      High            10

Signed-off-by: Vasyl Gello <vasek.gello@gmail.com>
Change-Id: Iae5998aee180c3ab43003407194bb2a462594a8c